ok 2008 fit sport auto 200K new plugs,wires,coil packs,o2 sensor,maf sensor,had decarb done about 2 months ago got 30mpg for about 2 weeks after that then back to 24/25 mpg wht you people think next humm

 

going to try some top tier gas next plus car running ruff till warms up

 

Yup I can verify running 91 gets you more gas mileage. however they are now gouging you big time for using better quality.. -.-

 

be ha
ppy to just avg 30 lol

 

well bigger trouble now drive side strut just broke off on the top end oh so sweet

 

damn that suck man :/

 

I guess you first have to fix the strut. For low mileage, look at the following easy fixes first.
Tire pressure. I have settled on 36 lbs as it gives me the best mileage with the least amount or wear.
Engine air filter. If you haven't looked at yours in a while, check it or replace it.
Check your driving habits. Your right foot can lose a lot of mileage.

If none of those things net you anything, have your car check for error codes. I bought a "Blue Driver" and pair it with my tablet and can read and clear codes. This may show that a sensor is bad.

I have a 2010 Honda Fit with a 5sp manual trans. With 130k+, I'm still averaging just under 38 mpg.

I can tell you that higher octane gas (Premium gas) will NOT get you better mileage. I have a spreadsheet of every fill-up for my car and the numbers for 87, 89 and even 91 Octane did not change my mpg. Further, there are lots of studies and presentations from folks that show that this is the case. Higher Octane does NOT get you better mileage.

If your thought is to clean the fuel system, get a bottle of fuel system cleaner and follow the directions. All fuels have detergents in them from low grade to premium. If you're looking to do an extra special cleaning, buy a bottle.

 

I can tell you 100% you WILL GET BETTER GAS MILEAGE. Because thats how the honda engineers designed the cars with the computer. ALL honda vehicles within the last 20 years will advance the timing when it detects higher octane fuels, and you WILL get better gas mileage. If you understood what timing does, and how different octanes effect your engine you wouldn't be saying this LOL I GUARANTEE you have not reprogrammed an ECU EVER, or had to retune fuel maps and ignition timing . I have done this test many times and im sick of arguing with ppl . IF you choose not to belive it , i dont care lol. I've done this test with 7 hr drives from ontario to Pennsylvania over a 100 times! with 3 different hondas . The exact same drive, same distance, 87 netted me max 650kms, while 94 netted me 780- 801 kms on ONE TANK.

EVEN with city driving the fit (GE8) tells you what you are averaging with your gas mileage. 87 octane I was getting 7. 5 L/ 100 k in city , and 6.4L/100k on highway, now repetitively I am getting 6.5L/100k in city , and 5.6 L/100k highway using 91 octane.

It made a difference on every single honda I've owened, an EG civic, DC2 integra, DC5 integra, FG2 civic SI , FG4 SI , my buddie's FA5, and my previous EP3 SIR's, My previous GD FIT , and my current GE8.

a 9th gen civic si will LITERALLY tell you how much kms you will get per tank and it will change depending on what fuel octane you use.

You can go ahead and live in ignorance if you choose, but don't spout bullshit because you are not properly educated on how engine uses different fuels with the ECU and timing to properly burn on time every ignition. The better the octane levels the more EFFICIENT it is burning the fuel therefore LESS FUEL is used because it can burn less of it to make the same power AND when you downgrade the octane MORE fuel is WASTED because it doesn't burn properly ON TIME everytime and the ECU retards the timing. Once that happens more fuel is wasted. PERIOD.

 

Thank you for that. What I will say is that I run 87 Octane and am getting just under 38 mpg during my 11 years of driving the car. I do keep a spreadsheet of every fill-up. So if you're right or I am is really a moot point in that he should be getting better than 25 mpg even with low grade fuel. So the issue lies elsewhere. He should be able to get 35 mpg once the issue is figured out and resolved. Then, he should be able to get more with premium gas if you're right. First we have to get him up over 30 mpg then we can debate the other.

 

Well this makes sense only if you go below the recommended type. Are you in Europe since yoiu're talking in l/100km? Here I only use 95 octane which is what most cars requrie, so of course using 87 instead (I don't even remember the last time I've even 87, wtf) might cause knock, forcing the ECU to compensate. But going above, to 100 octane or E85 or whatever isn't going to make it use less fuel. Because that's not what the engine was designed for.

 

To be clear, octane is measured differently in the U.S. vs. Europe so you can't compare the numbers.

Also- if the car would get better mileage with premium gas why would Honda keep this all a secret?

And for what it's worth higher octane gas is SO much more expensive these days that cost per mile would be greater, even if mileage improves.